题目：Asymptotic preserving schemes for radiative transfer systems
报告人：江松（Song Jiang）
北京应用物理与计算数学所研究员，中国科学院院士
时间地点：2021年9月29日上午9:30-10:30, 国家天元数学西南中心516报告厅
摘要：Radiative transfer systems find a wide range of applications, for example, in the inertial constrained fusion research and in astrophysics. The solution of a radiative transport system can cover both optical thin and optical thick regimes due to the large variation of photon's mean-free path and its interaction with the material. In the small mean free path limit, a nonlinear time-dependent radiative transfer system can converge to an equilibrium diffusion equation due to the intensive interaction among radiation and material. In the optical thin limit, the photon free transport mechanism will emerge. In this talk, we develope an asymptotic preserving unified gas kinetic scheme (AP-UGKS) for both grey and frequency-dependent radiative transfer systems, where the radiation transport equation is coupled with the material thermal energy equation. The newly developed scheme has the asymptotic preserving property in the optically thick regime to capture the diffusive solution without using a cell size being smaller than the photon's mean free path and time step being less than the photon collision time. Besides the diffusion limit, the scheme can capture the exact solution in the optical thin regime as well. Many numerical examples are included to validate the current approach. Extensions to more complex systems, including the equations of radiation hydrodynamics, will be presented. Moreover, we shall show an approach to mitigate the ray effects of the usual discrete ordinate (SN) method for the angular discretization.
报告人简介：
江松1982年从四川大学数学系毕业；1984年获西安交通大学硕士学位；1988年获德国波恩大学博士学位；1997年江松回国进入北京应用物理与计算数学研究所工作，历任研究室主任、科技委主任、副所长、党委书记；1998年入选国家“百千万人才工程”；2002年获得国家杰出青年科学基金资助；2014年被评为中国工程物理研究院杰出专家；2015年当选中国科学院院士。他主要从事可压缩流体力学数学理论、计算方法及应用研究。2019年11月18日获何梁何利科学与技术进步奖。
